Field of the Invention
The present invention relates to a method of producing reinforced polymeric cellular solids (foams) and precursor dispersions used in the method as well as articles formed thereby.
Background
Polymer foam systems are utilized in a wide variety of commercial applications, including the roofing, boat building, automotive, medical, aerospace and defense industries. Their light weight, conformability, great insulation qualities, relative high strength and ease of application technique make foam systems a popular choice among designers. However, in aggressive environments these systems have limitations even though basic material characteristics are desired to be deployed. For instance, a more robust urethane foam thermal protection system (TPS) can enhance the functionality of the new Ares I Crew Launch Vehicle (CLV) Upper Stage by providing better margins, better resistance to hail & launch pad debris damage, and reduced boil-off of cryogens for loiter periods on the Ares V follow-on vehicle. Boat builders could reduce laminate thickness, weight and labor costs for hulls with higher strength foam core systems. Use of such materials in roofing applications may provide longer life spans and resistance to damage in high wind areas.
There is a large body of knowledge in the reinforcement of elastomers, such as solid polyurethane elastomers, dating back to the early 1990's. However, very little success can be attributed to these efforts to reinforce flexible and rigid foams with glass, graphite, boron, aramid fibers or mica flakes to enhance their strength and/or flammability. This is primarily the result of not being able to vary chemistries effectively enough to achieve the desired final material qualities, misunderstanding of fiber length effects and functional changes when fibers are added to the raw materials.
Thus, there is a need in the art for reinforced polymeric foams useful in articles having thermal and mechanical properties superior to those found in currently available foam articles.